get selected row from a DTedit uiOutput object in shiny - r

Question

I need to capture the user selection from a DTedit table to build other tables.
I have used the input$<table>_rows_selected from a fresh DT objects but do not succeed doing it from a DTedit object.
I suspect that I need to build some intermediate object to capture the selection but cannot figure it out.
I added few lines to the DTedit demo code below to illustrate my issue.
Thanks for your help
library(shiny)
library(RSQLite)
library(DTedit); # devtools::install_github('jbryer/DTedit')
# Code modified from: https://github.com/jbryer/DTedit/blob/master/inst/shiny_demo/app.R
##### Load books data.frame as a SQLite database
conn <- dbConnect(RSQLite::SQLite(), "books.sqlite")
if(!'books' %in% dbListTables(conn)) {
books <- read.csv('books.csv', stringsAsFactors = FALSE)
books$Authors <- strsplit(books$Authors, ';')
books$Authors <- lapply(books$Authors, trimws) # Strip white space
books$Authors <- unlist(lapply(books$Authors, paste0, collapse = ';'))
books$id <- 1:nrow(books)
books$Date <- paste0(books$Date, '-01-01')
dbWriteTable(conn, "books", books, overwrite = TRUE)
}
getBooks <- function() {
res <- dbSendQuery(conn, "SELECT * FROM books")
books <- dbFetch(res)
dbClearResult(res)
books$Authors <- strsplit(books$Authors, ';')
books$Date <- as.Date(books$Date)
books$Publisher <- as.factor(books$Publisher)
return(books)
}
##### Callback functions.
books.insert.callback <- function(data, row) {
query <- paste0("INSERT INTO books (id, Authors, Date, Title, Publisher) VALUES (",
"", max(getBooks()$id) + 1, ", ",
"'", paste0(data[row,]$Authors[[1]], collapse = ';'), "', ",
"'", as.character(data[row,]$Date), "', ",
"'", data[row,]$Title, "', ",
"'", as.character(data[row,]$Publisher), "' ",
")")
print(query) # For debugging
dbSendQuery(conn, query)
return(getBooks())
}
books.update.callback <- function(data, olddata, row) {
query <- paste0("UPDATE books SET ",
"Authors = '", paste0(data[row,]$Authors[[1]], collapse = ';'), "', ",
"Date = '", as.character(data[row,]$Date), "', ",
"Title = '", data[row,]$Title, "', ",
"Publisher = '", as.character(data[row,]$Publisher), "' ",
"WHERE id = ", data[row,]$id)
print(query) # For debugging
dbSendQuery(conn, query)
return(getBooks())
}
books.delete.callback <- function(data, row) {
query <- paste0('DELETE FROM books WHERE id = ', data[row,]$id)
dbSendQuery(conn, query)
return(getBooks())
}
##### Create the Shiny server
server <- function(input, output) {
books <- getBooks()
dtedit(input, output,
name = 'books',
thedata = books,
edit.cols = c('Title', 'Authors', 'Date', 'Publisher'),
edit.label.cols = c('Book Title', 'Authors', 'Publication Date', 'Publisher'),
input.types = c(Title='textAreaInput'),
input.choices = list(Authors = unique(unlist(books$Authors))),
view.cols = names(books)[c(5,1,3)],
callback.update = books.update.callback,
callback.insert = books.insert.callback,
callback.delete = books.delete.callback)
# removed the second example
# added for this post using 'input$books_rows_selected' to capture the required info
output$selectedrow <- renderPrint({
s <- input$books_rows_selected
cat(paste0("selected ID:", s))
if (length(s)) {
cat(getBooks()[s,1])
}
})
}
##### Create the shiny UI
ui <- fluidPage(
h3('Books'),
uiOutput('books'),
verbatimTextOutput('selectedrow') # added for this post
)
shinyApp(ui = ui, server = server)

Answer 1

Here is a working example using a my modified version (v2.2.3+) of jbryer's DTedit:
My modified version of DTedit returns reactiveValues, including $rows_selected (only one row can be selected, though!).
library(shiny)
library(RSQLite)
library(DTedit); # devtools::install_github('DavidPatShuiFong/DTedit')
# Code modified from: https://github.com/jbryer/DTedit/blob/master/inst/shiny_demo/app.R
##### Load books data.frame as a SQLite database
conn <- dbConnect(RSQLite::SQLite(), "books.sqlite")
if(!'books' %in% dbListTables(conn)) {
books <- read.csv('books.csv', stringsAsFactors = FALSE)
books$Authors <- strsplit(books$Authors, ';')
books$Authors <- lapply(books$Authors, trimws) # Strip white space
books$Authors <- unlist(lapply(books$Authors, paste0, collapse = ';'))
books$id <- 1:nrow(books)
books$Date <- paste0(books$Date, '-01-01')
dbWriteTable(conn, "books", books, overwrite = TRUE)
}
getBooks <- function() {
res <- dbSendQuery(conn, "SELECT * FROM books")
books <- dbFetch(res)
dbClearResult(res)
books$Authors <- strsplit(books$Authors, ';')
books$Date <- as.Date(books$Date)
books$Publisher <- as.factor(books$Publisher)
return(books)
}
##### Callback functions.
books.insert.callback <- function(data, row) {
query <- paste0("INSERT INTO books (id, Authors, Date, Title, Publisher) VALUES (",
"", max(getBooks()$id) + 1, ", ",
"'", paste0(data[row,]$Authors[[1]], collapse = ';'), "', ",
"'", as.character(data[row,]$Date), "', ",
"'", data[row,]$Title, "', ",
"'", as.character(data[row,]$Publisher), "' ",
")")
print(query) # For debugging
dbSendQuery(conn, query)
return(getBooks())
}
books.update.callback <- function(data, olddata, row) {
query <- paste0("UPDATE books SET ",
"Authors = '", paste0(data[row,]$Authors[[1]], collapse = ';'), "', ",
"Date = '", as.character(data[row,]$Date), "', ",
"Title = '", data[row,]$Title, "', ",
"Publisher = '", as.character(data[row,]$Publisher), "' ",
"WHERE id = ", data[row,]$id)
print(query) # For debugging
dbSendQuery(conn, query)
return(getBooks())
}
books.delete.callback <- function(data, row) {
query <- paste0('DELETE FROM books WHERE id = ', data[row,]$id)
dbSendQuery(conn, query)
return(getBooks())
}
##### Create the Shiny server
server <- function(input, output) {
books <- getBooks()
my_results <- dtedit(input, output,
name = 'books',
thedata = books,
edit.cols = c('Title', 'Authors', 'Date', 'Publisher'),
edit.label.cols = c('Book Title', 'Authors', 'Publication Date', 'Publisher'),
input.types = c(Title='textAreaInput'),
input.choices = list(Authors = unique(unlist(books$Authors))),
view.cols = names(books)[c(5,1,3)],
callback.update = books.update.callback,
callback.insert = books.insert.callback,
callback.delete = books.delete.callback)
output$selectedrow <- shiny::eventReactive(
my_results$rows_selected, ignoreInit = TRUE, {
paste0("selected ID: ", my_results$rows_selected)
})
}
##### Create the shiny UI
ui <- fluidPage(
h3('Books'),
uiOutput('books'),
verbatimTextOutput('selectedrow') # added for this post
)
shinyApp(ui = ui, server = server)
Anyone running this example will actually need the .csv/.sqlite file, which is available in both jbryer DTedit and in my modified version.